Thermostatic lock fob the closures



'r. B. FOCKE ETAL 2,250,045

Filed Jan. 17, 1939 2 Sheets-Sheet 1 Oh \h July 22, 1941.

THERMOSTATIC LOCK FOR THE CLOSURES OF. COMBUSTION APPARATUS OR THE LIKE INVENFORS BY 12W ATTORNEYS,

July 22, 1941. 'r. a. FQCKE ETA].

THERMOSTATIC LOCK FOR THE CLOSURES OF COMBUSTION APPARATUS OR THE LIKE Filed Jan. 17, 1959 I 2 Sheets-Sheet 2 3 2 0 4; J 3 l a rfl 6 k4 w 2 fl 0 5 .MV J

D INVENTORS,

BY Y\- I Jlmfzwwwk ATTORNEU Patented July 22, .1941- THERMOSTATIC LOOK FOR THE'CLOSURES F COMBUSTION APPARATUS OR THE I LIKE Theodore B. Focke, Cleveland Heights,- and Evans W. vCheeseman, Cleveland, Ohio, assignors to Perfection Stove Company,

- corporation of Ohio Cleveland, Ohio, at

Application January 17, 1939, Serial No. 251,392 1 Claim. (01. 220-40) 'This invention is an automatic lock, of a thermosensitive or thermostatic character, for use with enclosures that are subjected, alternately,

to relatively low and high temperatures and are provided with openings through which access may be had to their interiors, said openings being equipped with closures; and it is the broad purpose of the invention to provide means for I preventing said closures from being opened when a relatively high temperature prevails within the enclosures. a

The invention was conceived in connection with liquid fuel burninga pparatus of the kind in which the fuel is fed to a b er bowl or firepot wherein it is vaporizedand receives primary air thereby to produce a relatively rich mixture. mixture, in an initial state of combustion, rises and, being rendered more highly combustible by the addition of secondary air, burns with practically-complete combustion in a combustion space or chamber above. The bowl or pot is provided with a relatively large lighting and clean-out opening normally closed by suitable means, desirably in the form of a plug. If .this closure or plug is removed when the apparatus is in operation ,and, as a consequence an abnormally high quantity or air is suddenly admitted to the bowl or pot, it causes an explosion ,resulting in a.

This I It is a more specific object' oi the invention,

therefore, to provide a thermostatic lock for the plugs or closures of the lighting and clean-out openings of combustion apparatus of the above described type; andalthough the invention is herein disclosed in this particular association,

cheapness in locking means of the kindreierred to -;Additional objects and advantages will appear in the course of the following description wherein reference is made to the accompanying drawings in which Fig. 1 is a fragmentary central vertical section through a liquid fuel burning apparatus incorporating the invention: Fig. 2.is a front elevation of the sleeve that surrounds the lighting and clean-out opening with the closure or plug positioned therein; Fig. 3 is a section on the line 3-4 of Fig. 1, looking in the direction indicated by the arrows; Fig. 4 is alongitudinal section through one side of the sleeve and plug showing thesposition the plug occupies with respect to the sleeve when the plug is-iully entered but before it is turned to secure it in place, the

thermostatic lock being in the position it occupies when the parts are relatively cool; and Fig. 5 is a view similar to Fig.4, showing the thermostatic lock in the effective position it assumes under the influence of a relatively high temperature and with the plug withdrawn as far as permitted by the lock.

The structure shown fragmentarily in Fig. 1 is that of a furnace incorporating liquid fuel combustion apparatus of the kind hereinbefore referred to. The burner bowl or firepot is designated I and includes an annular top wall-.2, the central opening of which is surrounded by a depending lip 3. Connected to and spaced above the top wall 2 bymeans or a number of shouldered rivets or the like, one of which is shownat 4 in Fig. 1, is an assembly comprising an annulus 5 flanged downwardly about its inner edge to form r a lip 6 that is spaced inwardly from and is substantially concentric with the lip 3; a top wall 1 oi a housing later to be described, and a ring like member 8, the outer rim portion of which is connected,as by iastening means or bolts 9, to the annular bottom wall chamber ll.

The top wall I constitutes a part of a housing, designated generally by the numeral II, which includes a peripheral wall I5 and a bottom wall IS, the latter having a central opening I? for admitting air to an air chamber designated 20 that is enclosed by said housing and surrounds the burner bowl or flrepot l. ,The top wall I of said housing has a central opening registering with the openings of the annulus 5 and the ringlike member 8, said'openings providing communication between the burner bowl or firepot and the combustion chamber H. From the chamber 20, primary air entersthe bowl or pot I through holes 25 in the peripheral wall thereof, and 'secondary air enters over the top wall of the bowl or pot and through the annular-slot between the lips 3 and 6, the lips serving to, deflect the secondary air downwardly. Liquid fuel is supplied to the sump-like bottom of the bowl or pot through a conduit 28 that leads from a suitable source of supply (not shown). Pursuant to usual practice, a liquid level control is included in the connections between the source and bowl or pot.

The peripheral wall of the bowl or pot I ad- .lacent the front 01' the apparatus is provided with a relatively large lighting and clean-out opening Ill of a combustion.

that is surrounded by a forwardly projecting flange 3 I A tube or sleeve 32 is suitably attached to the wall of the bowl or pot about the flange 3| and in concentric relation thereto and extends forwardly a considerable distance beyond the flange 3| and through an opening in the adjacent, portion of the peripheral wall ii of the housing I4. A bell-like member 35 surrounds the part of the tube or sleeve 32 forwardly of the wall l5 and its flanged outer end joins the front wall 36 of the furnace about an opening therein.

A closure, designated generally by the. reference numeral 4|! and presently to be described, is provided for the lighting and clean-out opening 30.

To start the fire, the closure is removed and a lighted match, taper or other igniting means is projected through the opening 30 to set fire to the fuel that has been fed to the bowl through the conduit 28. As soon as the fuel is ignited, the

closure 40 is replaced so as to tightly close the opening 30 and as the bowl becomes heated the fuel is vaporized and the vapors mix with primary air admitted through the holes 25. As combustion progresses and the heat increases vapors in greater volume are produced and ultimately a slowly burning gaseous body occupies the pot or bowl I and as the burning mixture rises it is rendered more highly combustible by the addition of secondary air that enters between the lips 3 and 6, the large percentage of the combustion occurring above this point and within the A combustion chamber.

The previously mentioned closure 40 is composed. of a cylindrical plug-like body 4| to the inner end wall of which is rotatablyconnected or swiveled, througha pivot member 42, a gasket carrier designated generally by the reference numeral 43. This element is desirably drawn or otherwise formed from a single piece of sheet metal and comprises a circular end wall 44 and a cylindrical wall 45 whose forward end is gradually curled outwardly and then back over itself to provide an inwardly facing annular channel that contains a ring 46 of suitable non-inflammable packing material, desirably of a fibrous nature, such as asbestos. The packing ring 46 is thus sustained in a position to engage the forward end of theflange 3| when the closure 40 is inserted into the tube or sleeve 32 by means 019. handle 48 attached to its forwardend The body 4| is enlarged at its forward end to nearly the internal diameter of the tube or sleeve 32 and at diametri cally opposedpoints is provided with slots Bl.

' The edge portions of the enlarged end of the body 4| arecut away on corresponding sides of both slots 50 to provide cam surfaces 5|. Diametrical- .ly opposed abutments 55, desirably in the nature I of rollers that are mounted on studs I, are carried by and project inwardly from the tube or sleeve in in a position to pass through. the slots Secured, as by rivets 60, to the cylindrical wall of the plug-like body 4| near the inner end there- I. when the closure is inserted into the tube or sleeve. Then when the plug-like body 4| isturned of and substantially in axial alignment with one of the slots 50 is the inner end of a bi-metal strip 8| that constitutes the thermo-sensitive or thermostatic element of the automatic locking means of our invention. Normally-that is, when the parts are coolthe outer free end of the strip 6| occupies substantially the position shown in Figs. 3 and 4 where it is disposed radially inwardly of the adjacent slot 50. When the parts become heated, the bi-metal strip assumes approximately the condition shown in Fig. 5 where its outer end is in a position to engage the con-,

tiguous abutment or roller 55 when an attempt is made to remove the closure 40, thereby to prevent such removal and avoid the dangerous condition arising from the sudden admission of an abn'ormally large quantity of air through the lighting and clean-out opening 30, such as would produce within the burner bowl or fire pot a more highly combustible mixture than normally prevails and that would explode and flash through the opening with theliability of causing injury to the person removing the closure and possible damage to clothing or other objects.

Having thus described our invention, what we claim is:

In combination, a sleeve arranged with one of its ends surrounding a closure seat, a plug in-- sertable within the sleeve and equipped at its inner end with a closure for engagement with the seat, the end of the plug remote from the closure being-enlarged and slightly less in diameter than theintemal diameter of the sleeve, the enlarged end of the plug having a slot that extends in a direction substantially longitudinally'of the plug and a cam surface extending from one side of said slot, an abutment projecting inwardly from the sleeve in a position to pass through said slot when the plug is inserted into the sleeve and to engage said cam surface when the plug is turned, thereby to hold the plug within the sleeve and the closure in engagement with the seat, and a bimetal strip arranged alongside the portion of the plug of lesser diameter and secured to the plug at its end remote from the enlarged end of the plug, said strip being 'so arranged that when it is affected by a relatively'high artificial temperature its free end-will assume a position to block passage of said abutment through said slot and prevent removal of the plug, said strip, under at- THEODORE B. FQCKE. EVANS w. cnnpsnmn. 

